The scientific method is a process for gathering data and processing information. It provides well-defined steps to standardize how scientific knowledge is gathered through a logical, rational problem-solving method. Figure 1 shows the steps of the scientific method.

Making observations. Observations may be qualitative (the sky is blue; water is a liquid) or quantitative (water boils at 100°C; a certain chemistry book weighs 2 kilograms).

Formulating hypotheses. A hypothesis is a possible explanation for an observation.

Performing experiments. An experiment is carried out to test a hypothesis. Experiments always produce new observations, and this brings the process back to the beginning again.

Scientists seek general relations that unify their observations. A concise verbal statement or a mathematical equation that summarizes a broad variety of observations and experience is known as scientific law. A familiar example is the law of gravity. It summarizes the experience that what goes up must come down.

Scientists also seek to understand laws. A tentative explanation of a law is called a hypothesis. A hypothesis is useful if it can be used to make predictions that can be tested by further experiments and can thereby be verified.

A hypothesis that continually withstands such tests is called a theory. A theory is an explanation of the general principles of certain phenomena that has considerable evidence or facts to support it. It may serve to unify a broad area and may provide a basis for explaining many laws.

Scientific progress is not smooth, certain and predictable. The path of any scientific study is likely to be irregular and uncertain. Progress is often slow, and many promising leads turn out to be dead ends. Serendipity (fortunate accidental discovery) as well as perseverance has played an important role in the development of science.